Managing the commercial harvest of kangaroos in the Murray-Darling Basin.

2004 ◽  
Vol 26 (1) ◽  
pp. 9 ◽  
Author(s):  
SR McLeod ◽  
RB Hacker ◽  
JP Druhan
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Wildlife Management ◽  
Structured Model ◽  
Harvest Rate ◽  
Stakeholder Groups ◽  
Commercial Harvest ◽  
Murray Darling Basin ◽  
Wide Range ◽  
Harvest Strategy

In this study a new, physiologically structured model of kangaroo population dynamics is described. The model has been used to examine a wide range of harvest rate � sex ratio combinations, following a simple harvest strategy where the quota was proportional to population size. The combinations of harvest rate and sex ratio in the harvest that best suited the objectives of the stakeholder groups (non-Government conservationists, wildlife management agencies, the kangaroo industry and pastoralists) were identified using multicriteria decision analysis. The best combinations for the stakeholder groups non-Government conservationists, wildlife management agencies and the kangaroo industry were characterised by a strong male bias (90 ? 100% male) and low to moderate harvest rates (10 ? 40% per annum). The best solutions for pastoralists were female biased (at least 70% females) with high harvest rates (90% per annum).

Wildlife management and the debate on the ethics of animal use. II. A challenge for the animal protection movement.

2012 ◽  
Vol 18 (2) ◽  
pp. 81 ◽  
Author(s):  
Daniel Lunney
Keyword(s):  
Wildlife Management ◽  
Critical Role ◽  
Animal Liberation ◽  
Ethical Imperative ◽  
Animal Protection ◽  
Wide Range ◽  
Animal Use

How people coexist and interact with animals has become an intensely debated issue in recent times, particularly with the rise of the animal protection movement following the publication of Peter Singer’s book Animal Liberation in 1975. This paper discusses some shortcomings of the philosophical positions taken in this complex debate. Singer has helped put animals on a new footing as a group that cannot morally be ignored, but his focus is mainly on individual, familiar animals that are used or abused by humans. The argument of this paper is that the ethics of managing wildlife hinges on a broader view of animals, and their contexts, than is apparent from Singer’s text. Wildlife managers aim to conserve populations of a wide range of species, and their habitats, but some mechanisms for achieving these aims, such as research and the control of invasive animals, are frequently opposed by elements of the animal protection movement. We need to adapt our attitude to animals, particularly wildlife, away from the traditional legacy of a few familiar species to embrace an ethic that is more ecological and relevant to Australian contexts. The case argued here has been to see the critical role of context — geographical, ecological, historical, relational — as a basis for a degree of reconciliation between conservation-oriented wildlife managers and the rising interest in the ethics of animal use. There is much to be gained for zoologists, wildlife managers and conservation biologists by framing key elements of their case in ethical arguments. Conversely, the challenge for those in the animal protection movement is to expand their philosophical ideas to include the ethical imperative of the conservation of populations of wildlife.

scholarly journals A Model for Analysing the Collective Dynamic Behaviour and Characterising the Exploitation of Population-Based Algorithms

2014 ◽  
Vol 22 (1) ◽  
pp. 159-188 ◽  
Author(s):  
Mikdam Turkey ◽  
Riccardo Poli
Keyword(s):  
Population Dynamics ◽  
Dynamic Behaviour ◽  
Fitness Landscape ◽  
Population Based ◽  
Levels Of Abstraction ◽  
Collective Dynamic ◽  
Model Studies ◽  
Proposed Model ◽  
Wide Range ◽  
Multiple Levels

Several previous studies have focused on modelling and analysing the collective dynamic behaviour of population-based algorithms. However, an empirical approach for identifying and characterising such a behaviour is surprisingly lacking. In this paper, we present a new model to capture this collective behaviour, and to extract and quantify features associated with it. The proposed model studies the topological distribution of an algorithm's activity from both a genotypic and a phenotypic perspective, and represents population dynamics using multiple levels of abstraction. The model can have different instantiations. Here it has been implemented using a modified version of self-organising maps. These are used to represent and track the population motion in the fitness landscape as the algorithm operates on solving a problem. Based on this model, we developed a set of features that characterise the population's collective dynamic behaviour. By analysing them and revealing their dependency on fitness distributions, we were then able to define an indicator of the exploitation behaviour of an algorithm. This is an entropy-based measure that assesses the dependency on fitness distributions of different features of population dynamics. To test the proposed measures, evolutionary algorithms with different crossover operators, selection pressure levels and population handling techniques have been examined, which lead populations to exhibit a wide range of exploitation-exploration behaviours.

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

Influence of operating conditions on population dynamics in nitrifying biofilms

1999 ◽  
Vol 39 (7) ◽  
pp. 5-11 ◽  
Author(s):  
Valentina Lazarova ◽  
Danièle Bellahcen ◽  
Jacques Manem ◽  
David A. Stahl ◽  
Bruce E. Rittmann
Keyword(s):  
Population Dynamics ◽  
Ammonia Oxidation ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Stable Operation ◽  
N Removal ◽  
Wide Range ◽  
Total Nitrogen Removal ◽  
Nitrite Oxidizers

TURBO N® is a circulating-bed biofilm reactor that provides stable operation and high N removal for a wide range of N and BOD loadings. This paper describes the influence of operating conditions on biofilm composition and population dynamics when the TURBO N® is operated to achieve tertiary nitrification, simultaneous carbon and ammonia oxidation and total nitrogen removal when coupled with a pre-denitrification fixed floating bed reactor. In situ specific nitrification rates and respiration tests showed that ammonium and nitrite oxidizers became less active in the biofilm once oxidation of influent BOD became important. Analyses of community structure with oligonucleotide probes targeted to the 16S rRNA showed the same general trends for nitrifiers, but also suggested shifts in the makeup of the ammonium and nitrite oxidizers that could not be detected with respirometry or specific nitrification rates.

scholarly journals Red fox sex ratio and changes in the number in the Krasnoarmeisky District of the Samara Region

2018 ◽  
Vol 7 (2) ◽  
pp. 111-115
Author(s):  
Olga Aleksandrovna Sklueva ◽  
Valeriy Vitalyevich Sklyuev ◽  
Rafik Ibragimovich Khakimov
Keyword(s):  
Population Dynamics ◽  
Sex Ratio ◽  
Vulpes Vulpes ◽  
Red Fox ◽  
Direct Impact ◽  
Age Composition ◽  
Behavioral Adaptations ◽  
Epizootic Process ◽  
Males And Females ◽  
Homeostatic State

The paper presents some data on the red fox ( Vulpes vulpes , Linnaeus, 1758) sex ratio in the Krasnoarmeysky District of the Samara Region. The results of winter trails traces of mammals show the placement of individual sites of males and females. The authors consider relationship between the population dynamics, sex and age composition and the placement of individual sites. Some aspects of behavioral adaptations and causes of changes in the number of animals in the study area are considered. The influence of a poaching factor on the dynamic indicators of the studied population and the possible danger of the epizootic process is described. A comparative analysis with the previously obtained data on the ratio of males and females in the litter is carried out. The paper indicates possible causes of animals number changes in the study areas. Poaching has a direct impact on the studied population homeostatic state maintaining mechanisms. There is also a forecast of poaching influence on deterioration of epidemiological and epizootic situation in the investigated region. In this paper we give recommendations to minimize possible damage by human activities.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Fish Populations ◽  
Native Fish ◽  
Partnership Model ◽  
European Settlement ◽  
Southeastern Australia ◽  
Murray Darling Basin ◽  
Wide Range ◽  
Funding Opportunities ◽  
Funding Cuts

<em>Abstract</em> .—The Murray–Darling basin (MDB) in southeastern Australia, covers 1.1 million km<sup>2</sup>, involves six partner jurisdictions with a myriad of different government agencies, and, hence, provides an excellent example of the complexities of multijurisdictional management across a range of social and political tiers. In the MDB, fish and fisheries compete for water with agriculture, which is the traditional water user and is driven by national economics. Murray–Darling basin rivers are now highly regulated and generally in poor health, with native fish populations estimated to be at only about 10% of their pre-European settlement abundances. All native commercial fisheries are now closed, and the only harvest is by a recreational fishery. The six partner jurisdictions developed a Native Fish Strategy (NFS) to rehabilitate native fish populations to 60% of pre-European settlement levels after 50 years of implementation by addressing priority threats through a coordinated, long-term, whole-of-fish-community (all native fishes) approach. As there are a wide range of stakeholders, broad engagement was needed at a broad range of government and community levels. The NFS funding was discontinued after 10 years, not because of its lack of successes or project governance, but due to jurisdictional political changes and funding cuts that resulted in a failure of the collaborative funding structure. The withdrawal of considerable funding by one jurisdiction led to collective decline in monetary contributions and posed a threat to the multijurisdictional structures for both water and natural resource management (NRM) within the MDB. As a consequence, there was a review and reduction in NRM programs and a subsequent reduction in focus to the core business of water delivery. Reflection on the NFS, however, provides some useful insights as to the successes (many) and failures (funding) of this partnership model. Overall, the strategy and its structure was effective, as exhibited by an audit of outputs, outcomes, and networks; by the evident ongoing advocacy by NRM practitioners and the community; and by the continuation of ideas under other funding opportunities. This has provided a powerful legacy for future management of fishes in the MDB.

scholarly journals Developing Harvest Strategies to Achieve Ecological, Economic and Social Sustainability in Multi-Sector Fisheries

2019 ◽  
Vol 11 (3) ◽  
pp. 644 ◽  
Author(s):  
Sean Pascoe ◽  
Toni Cannard ◽  
Natalie Dowling ◽  
Catherine Dichmont ◽  
Sian Breen ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Social Sustainability ◽  
Barrier Reef ◽  
Bottom Line ◽  
Export Markets ◽  
Ecological Economic ◽  
Stakeholder Groups ◽  
New Feature ◽  
Harvest Strategy ◽  
Ecosystem Based Fisheries Management

Ecosystem based fisheries management (EBFM) provides a framework to achieve ecological, economic and social sustainability in fisheries. However, developing harvest strategies to achieve these multiple objectives is complex. This is even more so in multi-sector multi-species fisheries. In our study, we develop such harvest strategies for the multi-species Coral Reef Fin Fish Fishery (CRFFF) operating in the waters of Australia’s Great Barrier Reef. The fishery includes recreational, charter and commercial sectors, and is a provider of regional employment and supplier of seafood to both local and export markets. We convened a series of stakeholder workshops and conducted surveys to identify stakeholder objectives and priorities, as well as potential harvest strategy frameworks for the fishery. These potential harvest strategies were assessed against the objectives using a further qualitative impact survey. The analysis identified which frameworks were preferred by different stakeholder groups and why, taking into account the different objective priorities and tradeoffs in outcomes. The new feature of the work was to qualitatively determine which harvest strategies are perceived to best address triple bottom line objectives. The approach is therefore potentially applicable in other complex fisheries developing harvest strategies which, by design, strive to achieve ecological, economic and social sustainability.

scholarly journals Population Structure of Harvested Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) on Prince Edward Island, Canada

2013 ◽  
Vol 126 (4) ◽  
pp. 288 ◽  
Author(s):  
Wendela Wapenaar ◽  
Fiep De Bie ◽  
David Johnston ◽  
Ryan M. O'Handley ◽  
Herman W. Barkema
Keyword(s):  
Population Dynamics ◽  
Wildlife Management ◽  
Urban Areas ◽  
Vulpes Vulpes ◽  
Prince Edward Island ◽  
Canis Latrans ◽  
Habitat Type ◽  
Red Foxes ◽  
Wild Canids ◽  
Agricultural Areas

An understanding of the population dynamics and habitat of wild Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) is a prerequisite to wildlife management. This information is also important in assessing the risk these wild canids pose to the public and domestic animals. On Prince Edward Island, information on age, sex, reproductive activity, and habitat use of 271 Red Foxes and 201 Coyotes was collected in the hunting and trapping season of 2004–2005. The estimated age of Red Foxes and Coyotes ranged from 0.5 to 13.5 years. A large proportion of harvested Red Foxes and Coyotes (58% and 48%, respectively) consisted of juveniles. The sex ratio was not significantly different from 1:1 for either species. Average litter size was 5.0 and 5.2 for Red Foxes and Coyotes, respectively. Number of placental scars ranged from 0 to 7 in Red Foxes and from 0 to 11 in Coyotes. Agricultural areas were the main habitat type (52%) of harvested Red Foxes. For harvested Coyotes, forest was the main habitat (44%), followed closely by agricultural areas (43%). Urban areas were a significant part (13%) of the habitat of Red Foxes. These data can be used to monitor population dynamics over time, provide information for wildlife management, and provide information on potential risk areas for disease transmission by wild canids.

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